IpSecManager and IpSecTransform API Cleanup

-Remove Int-based SPI usage from the IpSecTransform.Builder
 This is essentially a less-safe method overload, and it is both
 unnecessary and difficult to implement: the cross-validation
 between SPI and Transform is actually useful, and the kernel
 requires two different mechanisms to use an unreserved vs a
 reserved (alloc'd) SPI: CREATESA vs UPDATESA, which makes this
 hard to support. API Council has questioned the value of this,
 and they are right: everything points to "remove this". In the
 future, if we find that SPI reservation is overhead, we can
 always add it back.

-Hiding the TunnelMode builder method and application/remove
 methods. These will not land by the time the next API
 stabilizes, so better to hide them now that this is a
 near-certainty. Expectation is to un-hide them in the subsequent
 API bump.

Bug: 36073210
Test: Compilation, verified nobody is calling these stubs
Change-Id: Ic1a3f2cf7128633318ac175d6b56b45eb8d21cab
(cherry picked from commit 48b566557d5a66d4476008b3c59b815eb78cb373)

5 files changed, 3 insertions, 35 deletions

diff --git a/api/current.txt b/api/current.txt
index e0c9cf4ac5be..1b42fcc9af73 100644
--- a/api/current.txt
+++ b/api/current.txt
@@ -25590,7 +25590,6 @@ package android.net {
     method public android.net.IpSecTransform.Builder setAuthentication(int, android.net.IpSecAlgorithm);
     method public android.net.IpSecTransform.Builder setEncryption(int, android.net.IpSecAlgorithm);
     method public android.net.IpSecTransform.Builder setIpv4Encapsulation(android.net.IpSecManager.UdpEncapsulationSocket, int);
-    method public android.net.IpSecTransform.Builder setSpi(int, int);
     method public android.net.IpSecTransform.Builder setSpi(int, android.net.IpSecManager.SecurityParameterIndex);
   }
 
diff --git a/api/system-current.txt b/api/system-current.txt
index 0dd38a9de65b..464241201c0f 100644
--- a/api/system-current.txt
+++ b/api/system-current.txt
@@ -27718,12 +27718,10 @@ package android.net {
   public final class IpSecManager {
     method public void applyTransportModeTransform(java.net.Socket, android.net.IpSecTransform) throws java.io.IOException;
     method public void applyTransportModeTransform(java.net.DatagramSocket, android.net.IpSecTransform) throws java.io.IOException;
-    method public void applyTunnelModeTransform(android.net.Network, android.net.IpSecTransform);
     method public android.net.IpSecManager.UdpEncapsulationSocket openUdpEncapsulationSocket(int) throws java.io.IOException, android.net.IpSecManager.ResourceUnavailableException;
     method public android.net.IpSecManager.UdpEncapsulationSocket openUdpEncapsulationSocket() throws java.io.IOException, android.net.IpSecManager.ResourceUnavailableException;
     method public void removeTransportModeTransform(java.net.Socket, android.net.IpSecTransform);
     method public void removeTransportModeTransform(java.net.DatagramSocket, android.net.IpSecTransform);
-    method public void removeTunnelModeTransform(android.net.Network, android.net.IpSecTransform);
     method public android.net.IpSecManager.SecurityParameterIndex reserveSecurityParameterIndex(int, java.net.InetAddress, int) throws android.net.IpSecManager.ResourceUnavailableException, android.net.IpSecManager.SpiUnavailableException;
     field public static final int INVALID_SECURITY_PARAMETER_INDEX = 0; // 0x0
   }
@@ -27755,12 +27753,10 @@ package android.net {
   public static class IpSecTransform.Builder {
     ctor public IpSecTransform.Builder(android.content.Context);
     method public android.net.IpSecTransform buildTransportModeTransform(java.net.InetAddress) throws java.io.IOException, android.net.IpSecManager.ResourceUnavailableException, android.net.IpSecManager.SpiUnavailableException;
-    method public android.net.IpSecTransform buildTunnelModeTransform(java.net.InetAddress, java.net.InetAddress);
     method public android.net.IpSecTransform.Builder setAuthentication(int, android.net.IpSecAlgorithm);
     method public android.net.IpSecTransform.Builder setEncryption(int, android.net.IpSecAlgorithm);
     method public android.net.IpSecTransform.Builder setIpv4Encapsulation(android.net.IpSecManager.UdpEncapsulationSocket, int);
     method public android.net.IpSecTransform.Builder setNattKeepalive(int);
-    method public android.net.IpSecTransform.Builder setSpi(int, int);
     method public android.net.IpSecTransform.Builder setSpi(int, android.net.IpSecManager.SecurityParameterIndex);
     method public android.net.IpSecTransform.Builder setUnderlyingNetwork(android.net.Network);
   }
diff --git a/api/test-current.txt b/api/test-current.txt
index 0b499419ed56..0670e8380758 100644
--- a/api/test-current.txt
+++ b/api/test-current.txt
@@ -25703,7 +25703,6 @@ package android.net {
     method public android.net.IpSecTransform.Builder setAuthentication(int, android.net.IpSecAlgorithm);
     method public android.net.IpSecTransform.Builder setEncryption(int, android.net.IpSecAlgorithm);
     method public android.net.IpSecTransform.Builder setIpv4Encapsulation(android.net.IpSecManager.UdpEncapsulationSocket, int);
-    method public android.net.IpSecTransform.Builder setSpi(int, int);
     method public android.net.IpSecTransform.Builder setSpi(int, android.net.IpSecManager.SecurityParameterIndex);
   }
 
diff --git a/core/java/android/net/IpSecManager.java b/core/java/android/net/IpSecManager.java
index 83f4cc97b8fa..3fcdb7e28cf7 100644
--- a/core/java/android/net/IpSecManager.java
+++ b/core/java/android/net/IpSecManager.java
@@ -197,7 +197,6 @@ public final class IpSecManager {
      * @param transform an {@link IpSecTransform}, which must be an active Tunnel Mode transform.
      * @hide
      */
-    @SystemApi
     public void applyTunnelModeTransform(Network net, IpSecTransform transform) {}
 
     /**
@@ -242,7 +241,6 @@ public final class IpSecManager {
      *     network
      * @hide
      */
-    @SystemApi
     public void removeTunnelModeTransform(Network net, IpSecTransform transform) {}
 
     /**
diff --git a/core/java/android/net/IpSecTransform.java b/core/java/android/net/IpSecTransform.java
index 5c0bbe6a1437..74d60106c083 100644
--- a/core/java/android/net/IpSecTransform.java
+++ b/core/java/android/net/IpSecTransform.java
@@ -305,32 +305,9 @@ public final class IpSecTransform implements AutoCloseable {
          * given destination address.
          *
          * <p>Care should be chosen when selecting an SPI to ensure that is is as unique as
-         * possible. Random number generation is a reasonable approach to selecting an SPI. For
-         * outbound SPIs, they must be reserved by calling {@link
-         * IpSecManager#reserveSecurityParameterIndex(int, InetAddress, int)}. Otherwise, Transforms will
-         * fail to build.
-         *
-         * <p>Unless an SPI is set for a given direction, traffic in that direction will be
-         * sent/received without any IPsec applied.
-         *
-         * @param direction either {@link #DIRECTION_IN or #DIRECTION_OUT}
-         * @param spi a unique 32-bit integer to identify transformed traffic
-         */
-        public IpSecTransform.Builder setSpi(@TransformDirection int direction, int spi) {
-            mConfig.flow[direction].spi = spi;
-            return this;
-        }
-
-        /**
-         * Set the SPI, which uniquely identifies a particular IPsec session from others. Because
-         * IPsec operates at the IP layer, this 32-bit identifier uniquely identifies packets to a
-         * given destination address.
-         *
-         * <p>Care should be chosen when selecting an SPI to ensure that is is as unique as
-         * possible. Random number generation is a reasonable approach to selecting an SPI. For
-         * outbound SPIs, they must be reserved by calling {@link
-         * IpSecManager#reserveSecurityParameterIndex(int, InetAddress, int)}. Otherwise, Transforms will
-         * fail to activate.
+         * possible. To reserve a value call {@link IpSecManager#reserveSecurityParameterIndex(int,
+         * InetAddress, int)}. Otherwise, SPI collisions would prevent a transform from being
+         * activated. IpSecManager#reserveSecurityParameterIndex(int, InetAddres$s, int)}.
          *
          * <p>Unless an SPI is set for a given direction, traffic in that direction will be
          * sent/received without any IPsec applied.
@@ -447,7 +424,6 @@ public final class IpSecTransform implements AutoCloseable {
          *     properties is invalid.
          * @hide
          */
-        @SystemApi
         public IpSecTransform buildTunnelModeTransform(
                 InetAddress localAddress, InetAddress remoteAddress) {
             //FIXME: argument validation here